The invention relates to air filters and more particularly to electric air filters.
Recirculating air filters are self contained air cleaning units that are designed to supplement existing ventilation systems. In contrast to the conventional air filtration system that removes contaminated air from a room, the recirculating air filter cleans the contaminated air within the room by recirculating the room air through a filter in a multi-pass operation.
Recirculating air filters have become very popular in recent years to remove particulates from industrial work environments because of the substantial savings in heating and cooling costs. Portable room air cleaners that recirculate filtered air into the room have also become widely used in office and factory environments. These portable recirculting air filters supplement the existing ventilation system. The key difference between a conventional air filter and a recirculating air filter is that the recirculating air filter discharges its exhaust into the same volume that is being filtered while the conventional air filter discharges its exhaust into another volume. The same filter element may be used in either application.
There are many commercially available recirculating air filters that use mechanical air filter media or electrostatic precipitator elements. These commercial units have disadvantages that place serious limitations on their performance and application. The recirculating air filter using mechanical air filter media suffer because the air flow resistance increases sharply as the filter efficiency increases. Thus, a compromise is required between the amount of air passing through the cleaner and the efficiency of the cleaner. Adding a more powerful air blower to increase the air flow is undesirable because of increased initial cost, energy consumption and noise. In an office environment, noise is often the most important factor. The major problems with recirculating air filters using electrostatic precipitator elements are the ozone generation and the high initial cost. The recirculating electric air filter in this invention overcomes the limitations of commercially available units.
Typical available filter cartridges are sealed units consisting of high voltage and ground electrodes, filter media and support and sealing flanges. These cartridges were designed to have repeated cycles of particle deposit formation and removal prior to discarding the entire unit when the filter reaches its maximum dust holding capacity. The replacement of these prior art filter cartridges on a very frequent schedule to meet the 10 gram limit is impractical because of the filter costs, labor costs, and costs for interrupting the fuel fabrication process. Also the filter cartridge unit cannot be easily disassembled or compressed for reduction of the volume of waste for disposal.
In the fuel processing application it is desirable to maintain the general configuration of a cylindrical filter cartridge which mounts onto a blower. However, instead of the filter cartridge being an integral unit, a cartridge designed for easy disassembly and replacement of the filter media is highly advantageous. It is also desirable to make the entire unit as compact as possible.
Accordingly, it is an object of the invention to provide a filter cartridge which can be easily disassembled and reassembled.
It is also an object of the invention to provide a filter cartridge in which the filter media can be readily replaced.